Unicorns
are fierce, intelligent creatures of the forest, noble beasts who keep
their own counsel and typically appear only to defend their homes
against evil. They universally shun all creatures except for
good-aligned fey, good-aligned humanoid women, and the woodlands'
native animals, though they may fight alongside other good creatures
against common enemies. A typical unicorn is 8 feet long and 5 feet
tall at the shoulder, weighing 1,200 pounds.

Unicorns mate
for life, and the pairs generally make their homes in specific glades
or dells within the vast forests they protect (these regions can cover
anywhere from a few dozen square miles to hundreds). They allow good
and neutral creatures to pass through, hunt for food, or reside in
their woods unharmed, but evil creatures and those who damage the local
ecosystem more than necessary through sport hunting or commercial
logging are swiftly driven out or killed. On rare occasions, lone
unicorns without mates or whose partners have been slain have been
known to adopt young women of exceptionally pure virtue as surrogates,
allowing the women to ride on their backs and becoming their guardians
and protectors for life. This bond generally ends amiably if the woman
becomes more committed to someone else—such as a lover or child—giving
rise to the myth that unicorns only befriend virgins.

A
unicorn's horn is the focus for its powers, and in order to use its
spell-like abilities on other creatures the unicorn must touch them
with it. Evil creatures greatly value unicorn horns as reagents for
healing potions and other dark rites, and a single powdered unicorn
horn counts as 1,600 gp when used as a component for crafting healing
magic.